Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
  • F01N13/18—Construction facilitating manufacture, assembly, or disassembly
  • F01N13/1838—Construction facilitating manufacture, assembly, or disassembly characterised by the type of connection between parts of exhaust or silencing apparatus, e.g. between housing and tubes, between tubes and baffles
  • F01N13/1844—Mechanical joints
  • F01N13/185—Mechanical joints the connection being realised by deforming housing, tube, baffle, plate, or parts thereof
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
  • B21C37/00—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape
  • B21C37/06—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape of tubes or metal hoses; Combined procedures for making tubes, e.g. for making multi-wall tubes
  • B21C37/12—Making tubes or metal hoses with helically arranged seams
  • B21C37/123—Making tubes or metal hoses with helically arranged seams of coated strip material; Making multi-wall tubes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
  • B21C37/00—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape
  • B21C37/06—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape of tubes or metal hoses; Combined procedures for making tubes, e.g. for making multi-wall tubes
  • B21C37/15—Making tubes of special shape; Making tube fittings
  • B21C37/156—Making tubes with wall irregularities
  • B21C37/157—Perforations
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L59/00—Thermal insulation in general
  • F16L59/14—Arrangements for the insulation of pipes or pipe systems
  • F16L59/143—Pre-insulated pipes
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L9/00—Rigid pipes
  • F16L9/16—Rigid pipes wound from sheets or strips, with or without reinforcement
  • F16L9/165—Rigid pipes wound from sheets or strips, with or without reinforcement of metal
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
  • F24F13/00—Details common to, or for air-conditioning, air-humidification, ventilation or use of air currents for screening
  • F24F13/02—Ducting arrangements
  • F24F13/0245—Manufacturing or assembly of air ducts; Methods therefor
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
  • F24F13/00—Details common to, or for air-conditioning, air-humidification, ventilation or use of air currents for screening
  • F24F13/02—Ducting arrangements
  • F24F13/0263—Insulation for air ducts
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
  • F24F13/00—Details common to, or for air-conditioning, air-humidification, ventilation or use of air currents for screening
  • F24F13/02—Ducting arrangements
  • F24F13/0281—Multilayer duct
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
  • F24F13/00—Details common to, or for air-conditioning, air-humidification, ventilation or use of air currents for screening
  • F24F13/24—Means for preventing or suppressing noise

Definitions

• the present invention relates to double-walled structures, such as silencers for use in ventilation duct systems.
• the invention also concerns the production of such double-walled structures.
• the invention is related to the field of producing helically-wound lock-seam tubing, in particular for circular ventilation duct systems.
• Background Art Double-walled structures for use in ventilation duct systems are well known in the art. In a brochure entitled "LindabSilencer" printed in 1988 and distributed by Lindab Ltd., various double-walled silencers are disclosed. On p. 2 of this Lindab brochure, the general construction of such silencers is described.
• a typical Lindab silencer comprises an inner tube of perforated thin metal sheet and an outer tube or casing which typically is a helically-wound lock-seam tube of thin metal sheet.
• the space between the two tubes is filled with sound-absorbing material, such as mineral wool, of different types and densities depending on the field of use.
• sound-absorbing material such as mineral wool
• the thin fibre layer for covering the perforated inner tube is provided in the following manner.
• the shape of the fibre material piece is adapted to the shape and circumference of the perforated inner tube.
• Second, the cut fibre material piece is swept about the perforated inner tube, and third the fibre piece is fastened thereon, for instance by means of adhesive. Again, these are separate operations.
• the operations are time-consuming and are often carried out manually, which is disadvantageous.
• the unnecessarily complicated operations for applying the fibre layer increase the total cost of the double-walled struc- ture.
• An object of the invention is to eliminate the drawbacks mentioned above by providing an improved double- walled structure. Another object of the invention is to provide an improved method and an improved apparatus for producing the double-walled structure in such a manner that the above- mentioned drawbacks are eliminated.
• the double-walled structure itself as well as the production thereof can be remarkably simplified. No manual operations are required, but the inner perforated tube covered by the fluid-permeable material can be produced continuously in one machine, which has desirable advantages in that fewer and simpler operations are carried out, whereby the production is rationalised.
• the cover of fluid- permeable material is securely fastened tightly on the perforated inner tube. Normally no additive is needed, and the production is simplified and more effective than prior-art techniques.
• the longitudinal edge portions of the strip of fluid-permeable material are secured in the helical lock seam of the perforated tube, which significantly reduces the risk that the fluid-permeable cover comes loose from the tube.
• the invention is applicable to many kinds of double- walled structures, such as long ventilation ducts which are provided with insulating material over their full length and which have no end pieces. Further, it should be noted that the double-walled structure of the invention is applicable to other products, such as filter assemblies in which the space between the tubes is fill- ed with filter material for filtering various fluids.
• Fig. 1 is a perspective view from above of an arrangement for producing a double-walled structure in accordance with an embodiment of the invention
• Fig. 2 is a cross-section along the line II-II in Fig. 1 showing a metal strip, a cloth strip and guiding plates,
• Fig. 3 is a cross-section of a tubing fed out of a forming head, along the line III-III in Fig. 1,
• Fig. 4 is a detail of Fig. 3 showing on a larger scale a cross-section of a lock seam of the tube
• Fig. 5 shows the application of a piece of filler material on the tubing produced in the arrangement shown in Fig. 1,
• Fig. 6 shows the insertion of the tube assembly in an outer tube
• Fig. 7 shows the mounting of an end piece on one end of the double-walled structure.
• Fig. 1 shows an arrangement for producing a double- walled structure in accordance with a presently preferred embodiment of the invention.
• the double-walled structure is a silencer for use in a ventilation duct system (see Fig. 7) .
• the arrangement comprises a machine 1 for producing helically-wound lock-seam tubing 2, a schematically shown apparatus 3 for applying filler material, here sound- absorbing material, on the outside of the tubing 2 such that the tubing 2 and the sound-absorbing material form a tube assembly (see Fig. 5) , and a schematically shown apparatus 4 for enclosing said tube assembly in a casing (see Figs 6-7) .
• the two apparatus 3 and 4 may be of known construction and are therefore not described in detail here.
• the machine 1 comprises a forming head 5 for forming the helically-wound lock-seam tubing 2 which is fed out of the forming head 5 (arrow A) . Further, the machine 1 has a drive roller assembly 6 for feeding a first strip 7 which is wound on a reel 7a to the forming head 5 (arrow B) . The rollers of the drive roller assembly 6 are driven by a drive unit 8. Guiding plates 9 and 10 are provided for guiding the first strip 7 into the forming head 5 (see Fig. 2) .
• a cutting unit 11 is provided for cutting the tubing 2 into suitable, predetermined lengths.
• the cutting unit 11 may be of a type known in the art and need not be described in detail here.
• the first strip 7 is a perforated metal strip which forms the body of the tubing 2 fed out of the forming head 5 and having a helical lock seam 12.
• a second strip 13 wound on a reel 13a is fed to the forming head 5 by means of the drive roller assembly 6.
• the two strips 7 and 13 are joined in the drive roller assembly 6 and fed together as a composite strip into the forming head 5, in which this com- posite strip is helically formed into the tubing 2. It is preferred that the two strips 7 and 13 have substantially the same width.
• the air-permeable strip 13 is a cloth material, preferably a polymer material
• the metal strip 7 is of thin metal sheet.
• Fig. 2 illustrates the two guiding plates 9 and 10 and the two strips 7 and 13 (the plates and strips being shown somewhat spaced apart for clarity reasons) .
• the two longitudinal edge portions 14 and 15 of the metal strip 7 are edge-formed as shown in Fig. 2 by means of edge-forming rollers 6a (see Fig. 1) .
• This forming of the edge portions 14 and 15 is carried out in order to obtain a secure lock seam 12 of the tubing 2.
• the cloth strip 13, which has longi- tudinal edge portions 16 and 17, is held on the upper surface of the lower guiding plate 10.
• the lower guiding plate 10 has a V-shaped groove 18, which corresponds to the V-shaped edge portion 14 of the metal strip 7.
• the guiding plates 9 and 10 serve to guide the two strips 7 and 13 applied together in a secure manner into the forming head 5.
• Fig. 3 shows a cross-section of the tubing 2 after the forming head 5.
• the two strips 7 and 13 are helically wound together, and the cloth strip 13 tightly covers the perforations of the metal strip 7 forming the body of the tubing 2.
• FIG. 4 A cross-section of the lock seam 12 of Fig. 3 is shown in detail in Fig. 4.
• the two bent edge portions of the tube wall of the lock seam 12 are shown at a small distance from each other in Fig. 4.
• these tube edge wall portions are clinched together in order to obtain a secure lock seam 12.
• the edge portions 16 and 17 of the cloth strip 13 are lock-seamed together with the edge portions 14 and 15 of the metal strip 7 such that the edge portions 16 and 17 of the cloth strip 13 are securely fastened in the helical lock seam 12 of the tubing 2.
• the tubing 2 fed out of the forming head 5 is adapted to form the inner tube of a silencer for use in a ventilation duct system.
• the final steps for producing the silencer are shown in Figs 5-7.
• Fig. 5 shows how a rectangular piece 19 of a filler or sound-absorbing material, preferably wool, is swept around the tubing 2 (arrows C) consisting of a perforated inner tube body formed of the metal strip 7 and covered by an air-permeable layer formed by the cloth strip 13.
• a filler or sound-absorbing material preferably wool
• the wool piece 19 is applied on the outside of the tubing 2, and this tube assembly 2, 19 is inserted in a tubular casing 20 coaxial with the inner tube (see Fig. 6, arrow D) .
• the casing 20 is a helically wound lock- seam tube formed from a strip of thin metal sheet.
• Fig. 7 shows how an end piece 21 is mounted on one end of the casing 20 (arrow E) .
• the casing 20 is provided with one end piece 21 at each end.
• Each end piece 21 has a tubular portion 22 for connection to circular ducts (not shown) in a ventilation duct system.
• the manufacturing of the aimed-at double-walled silencer is finished.
• the inner tube 2 is a first wall and the outer tube 20 is a second wall.
• the shape of the casing 20 is not crucial; it may alternatively have other forms and cross-sections, such as elliptic, rectangular, etc.
• the perforated metal strip 7 is fed to the forming head 5 together with the cloth strip 13 applied to that side of the metal strip 7 which forms the outside surface of the tube body.
• the two strips 7 and 13 are helically wound as a composite strip in the forming head 5, and the edge portions 16 and 17 of the cloth strip 13 are secure- ly fastened in the helical lock seam 12.
• the tubing 2 consisting of the perforated, helically wound strip 7 covered by the likewise helically wound cloth strip 13 is cut in a suitable length corresponding to the aimed-at silencer.
• the sound-absorbing ate- rial 19 is applied to the outside surface of the tube 2, and finally the tube assembly 2, 19 consisting of the helically wound tubing 2 and the sound-absorbing material 19 applied thereon is inserted in the tubular casing 20.
• the casing 20 is closed by two end pieces 21.
• tubing 2 lengths of tubing 2 are put in an intermediate supply before providing the sound-absorbing mate- rial 19 on the tubing 2 and before insertion of the tube assembly 2, 19 in the outer tube or casing 20.
• the filler material to be applied on the tubing fed out of the forming head can either be applied in the shape of a rectangular piece which is swept around the tubing, or applied in the shape of a strip which is helically wound on the outside of the tubing (not shown) . Of course, there are other alternatives for applying the filler material.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Manufacturing & Machinery (AREA)
• Exhaust Silencers (AREA)
• Rigid Pipes And Flexible Pipes (AREA)
• Pipe Accessories (AREA)
• Drying Of Gases (AREA)
• Making Paper Articles (AREA)

Priority Applications (8)

Applications Claiming Priority (4)

Publications (1)

Family

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Family Applications (1)

Country Status (10)

Cited By (3)

Families Citing this family (2)

Citations (3)

Family Cites Families (2)

• 1998
  • 1998-01-26 DE DE69820651T patent/DE69820651T2/de not_active Expired - Lifetime
  • 1998-01-26 EP EP98901653A patent/EP1015146B1/en not_active Expired - Lifetime
  • 1998-01-26 AU AU57884/98A patent/AU5788498A/en not_active Abandoned
  • 1998-01-26 WO PCT/SE1998/000103 patent/WO1998032551A1/en active IP Right Grant
  • 1998-01-26 DK DK98901653T patent/DK1015146T3/da active
  • 1998-01-26 PL PL98335032A patent/PL186145B1/pl unknown
  • 1998-01-26 CZ CZ0248899A patent/CZ300247B6/cs not_active IP Right Cessation
  • 1998-01-26 CA CA002277204A patent/CA2277204A1/en not_active Abandoned
  • 1998-01-26 HU HU0000837A patent/HU223181B1/hu active IP Right Grant
• 1999
  • 1999-07-14 NO NO19993464A patent/NO312181B1/no not_active IP Right Cessation

Patent Citations (3)

Non-Patent Citations (3)

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